Embedded interview question 3

1. Can a local variable be renamed with a global variable? A: Yes, it will partially block the global 2. How to reference a defined global variable A: Can extern3. can a global variable be defined in a header file that can be included in multiple. c files? A: Yes. You can declare a global variable with the same name in static form in different C files. 4. What is the problem with the statement for (; 1? What does it mean? Answer: endless loop 5. in the program, global variables and static variables exist in (Global Data zone) local variables exist in (stack), dynamic application data exist in (HEAP) 6. what is the difference between a queue and a stack? Answer: queue first-in-first-out, stack first-in-first-out 7. What is the implementation of a frequently-used short function in C? What is C ++? A: C is defined by a macro, and C ++ uses inline8. determine the module functions and module interfaces. The module interfaces were completed during the software design period. A: Design Overview 9. what is the difference between a reference and a pointer? Answer: 1) the reference must be initialized, And the pointer does not need to be 2) the reference cannot be changed after initialization, And the pointer can change the object referred to. 3) there is no reference pointing to a null value, there is a pointer pointing to a null value 10. basic Features of RTOS answer: real-time performance and reliability 11. what is a balanced binary tree? A: The left and right Subtrees are balanced binary trees, and the absolute value of the depth difference between the left and right Subtrees is less than 112. What causes stack overflow? A: No garbage collection. 13. The constructor cannot be declared as a virtual function. 14. Which network protocol does the Internet use? What is the main hierarchy of the protocol? Answer: TCP/IP, application layer, transport layer, network layer, and physical layer (data link layer) 15. What protocol is used for the conversion of Internet physical addresses and IP addresses? Answer: ARP (Address Resolution Protocol) 16. define a macro to compare the sizes of two numbers A and B. The value cannot be greater than or less than. If Statement A: # define max (a, B) (a/B )? A: b17. write a virus while (1) {int * P = new int [100000000];} 18. evaluate the length of a string. Two Methods: int mystrlen (char * s) {int Len = 0; while (* s ++) Len ++; return Len ;} int mystrlen (char * s) {char * STR = s; while (* Str) STR ++; Return (STR-S);} 19. string Copy char * mystrcpy (char * DST, const char * SRC) {char * ret = DST; while (* RET ++ = * SRC ++); Return DST ;} 20. in-memory replication void * mymemcpy (void * _ DST, const void * _ SRC, unsigned Len) {unsigned char * DST = _ DST; const unsigned char * src = _ SRC; while (Len --> 0) {* DST ++ = * SRC ++;} return _ DST ;}